This invention relates generally to the accurate and convenient measurement of supply and exhaust airflows through a ventilating apparatus, generally of the type used in conjunction with a restaurant cooker, or the like, so that adjustment can be made in the supply air entering into the hood, or to the exhaust air being exhausted, to provide for that more precise quantities of air circulation therethrough and to minimize the energy requirements for the facility in which this invention is installed.
There are numerous types of ventilating hoods that are primarily used in conjunction with restaurant operations, or other types of facilities in which fumes may be generated, and are required for removal, and usually if these ventilating hoods are not properly balanced in their operations, they either will introduce too much of the outside air into the building, or exhaust an inordinate amount from the structure which may be more than is than required for attaining the convenient and proper circulation and ventilation of the building in which the apparatus is installed. This is not to say that the variety of ventilating hoods as developed, patented, and upon the market, do not operate satsifactorily, since most of them do. On the other hand, the essence of this particular invention is to provide a means for finely tuning the operations of such hoods, so that the more precise amount of supply air will be introduced into the hood, and into the facility in which it is installed, and likewise, a more exact amount of exhaust air will be drawn therefrom, as a result of the initial and precise calibration for these operational characteristics for such a hood, and the periodic measuring of these airflow capacities to assure that the hood has not become misaligned in its functioning.
As an example, the U.S. Pat. No. 4,286,572, upon a ventilating hood, and owned by the assignee of the invention of this current application, shows a style of ventilating hood that incorporates both a supply inlet, an exhaust outlet, and the incorporation of both a supply fan and exhaust fan for attaining the proper movements of airflow through the hood, and primarily for achieving the elimination of fumes from the kitchen or room in which the ventilating hood of this invention is installed. And, as can be readly understood, and as is so thoroughly described in the specification for that earlier patent, it is highly desirable to maintain a proper balance between the amount of incoming air introduced into the facility, through the supply inlet for the hood, and likewise, to achieve that proper balance for exhaust, so that the fumes from the cooking surface will be adequately absorbed into the flow of air through the hood, and out of its exhaust, drawing only a small amount of the ambient and heated or cooled air from the kitchen or room in which the hood is installed, out through the said exhaust outlet. For example, if the exhaust fan or blower is set at too high of a capacity, and which generates an excess of exhausting air from the hood, and the room in which it is installed, then during the summer months, too much of the air conditioned air within the kitchen will be drawn through the exhaust, or during the winter months, too much of the heated air within the kitchen will be drawn through the exhaust, both leading to a needless waste of conditioned air, and the energy consumed in generating it. In addition, if the supply intake is set too low, then, a similar waste of conditioned air takes place. Thus, it can be readily determined that these ventilating hoods must be properly set to precise operations, so that they will operate highly satisfactory for drawing off those fumes from the cooking surface, or from any other apparatus that is used in conjunction with this hood, but at the same time, not operate too excessively or deficiently that the other energy requirement for the facility in which it is installed are unduly taxed leading to needless waste of energy and the incurrence of excessive cost therefor.
A variety of prior patents showing various styles of hoods have been uncovered in a search for prior art relating to this style of invention. For example, U.S. Pat. No. 3,285,154, to De Rosa, shows what is identified as a positive direct relief means for exhaust systems, and which includes various damper means within either the supply inlet or exhaust outlet, and which can be regulated for gauging the amount of air passing through the hood. But, it does not appear that any type of calibration means is associated with this hood and which could provide for immediate testing and gauging for resetting of such instrumentalities so as to assure that a proper functioning and operation is sustained for the shown hood. The U.S. Pat. No. 3,387,434, to Stalker shows a pair of motor operated blowers for effecting supply intake and exhaust for a ventilating hood, but it does not indicate that any precise gauging or calibration is provided for setting or resetting of the air flows passing through the shown hood. The U.S. Pat. No. 3,513,766, to Ahlrich shows a dual air flow device, but it does not show that any precise efficiency for regulation of the airflows is provided within this style of ventilating hood. The U.S. Pat. No. 4,085,735, to Kaufman, shows an air ventilation and washing system, wherein apparently temperature sensing means are provided, but generally for affording fire detection and extinguishing in the event that a grease flash fire, or the like, should occur. The U.S. Pat. No. 4,089,327, to Welsh shows a kitchen exhaust system, where particular quantities of airflow are maintained, but not done so through a pressure regulating mechanism. The U.S. Pat. No. 4,117,833, to Mueller does show an exhaust hood, with adjustable air injection nozzling system, but it is not of any regulated quantity. Although, it is to be noted that the nozzle does incorporate restriction baffles in order to throttle the airflow through the nozzle spout. The U.S. Pat. No. 4,133,300, to Burton, Jr., shows a ventilating range hood, with means for directing airflow within the hood, but does not explain how any pressure may be detected for providing for fine regulation in the flow of air through the shown hood. The U.S. Pat. No. 4,166,448, to Miller, is also upon a ventilation system. And, energy efficiency is apparently maintained through this hood, but not by any controlling of its airflow. The U.S. Pat. No. 4,134,394, to Otenbaker, shows an air ventilation system wherein the temperature of the air is controlled between summer and winter times, so as to provide a desirable working temperature within the kitchen in which the system is installed. The U.S. Pat. No. 4,177,716, to Bowe, does touch upon the concept of providing automatic energy savings within an exhaust system. It discloses an exhaust system control apparatus operating to achieve automatic closure to its damper, in this particular system, or an exhaust duct leading from a spray booth. And, the damper motor is energized to open its said damper when the spray booth is in operation, and likewise, is automatically reversed for controlling the damper into closure, at the termination of a spraying operation. Thus, energy saving is attained, simply by opening and closing of a damper, but not providing for a fine regulation in the operations of the exhaust system through pressure detection. The U.S. Pat. No. 4,346,692, to McCauley, discloses a make-up air device for range hood. In this particular device, once again, control of the air is obtained through adjustable louvers, but it does not appear that there is any precise or fine regulation of the intake air, or its exhaust, by means of pressure regulation or detection. The U.S. Pat. No. 4,373,509, to Neitzel shows a high efficiency ventilation system. As can be seen, it pertains to the regulation of the amounts of fresh air and temperature air handled by the damper, without significantly altering the total amount of supply make-up air passing through the hood. And, the system does recognize that adjustment can be made to the operations of the device so as to use more or less of the temperate air depending upon the conditions around the cooking instrument. And, while the particular ventilation system, and its hood, describes the use of a variety of registers, dampers, and the like, for regulating airflow, there is nothing in this disclosure, upon a review, that explains just how precisely such air flow can be controlled through the use of any pressure detecting means, such as envisioned for the particular invention of this application.
It must also be commented, with respect to the current invention, and the background information relating to it, that pressure regulators, manometers, and the like, have been available for many, many years. But, applicant has not found where such devices have been incorporated into the structure of a ventilating hood, or which have been used in conjunction with such a hood, in order to provide for a very fine calculation and calibration in the operations of ventilating hood, for controlling precisely the amount of intake air supplied to and through the hood, or the amount of exhaust exiting therefrom. This is the essence of this current invention.
It is therefore, the principal object of this invention to provide a procedure for determining both supply and exhaust airflows through a ventilating hood, in order to provide for a very quick and prompt adjustment in their settings, and assure that the ventilating hood is operating at peak efficiency.
Another object of this invention is to provide a ventilating hood that incorporates a means for detecting, through pressure differential, a precise quantity of airflow passing through the hood, and thereby obviate the situation that currently prevails wherein most ventilating hoods currently in use are incapable of attaining air balance measurements, or to control precisely the airflows therethrough.
Another object of this invention is to provide means for achieving accuracy and consistency in the operations of the supply and exhaust fans for a ventilating hood, and thereby achieve energy savings in the sustained operations of such a hood.
Another object of this invention is to provide a precalibration, or a calibration at the factory, of a ventilating hood just after its manufacture, so that the hood can be installed for more accurate operations at a particular site, and can be reset periodically through the application of this current invention to assure that the hood sustains its accurate functioning.
Another object of the current invention is to provide means affiliated with particular locations of a ventilating hood so that airflows can be immediately determined, to assure the maximum and efficient operation of a ventilating hood in its particular setting and installation.
These and other objects will become more apparent to those skilled in the art upon reviewing the summary of this invention, and upon undertaking a study of the description of the preferred embodiment, in view of the drawings.